1. Field of the Invention
The present invention relates to a particle analyzing apparatus and a method therefor, and more particularly to an apparatus that can express in a value to what extent the distribution data obtained as a result of the particle analysis is similar to the reference distribution data. The apparatus is useful for analyzing various particles in blood.
2. Description of the Related Art
Conventional particle analyzing apparatus include one that provides measured data concerning a plurality of particles to classify the particles measured based on the difference in such measured data. For example, when hemocytes are measured as the above particles, a sample in which hemocytes are suspended is successively supplied to a particle detection unit. Every time particles are detected in the detection unit, the unit generates two kinds of data items X1 and X2. Data items X1 and X2 obtained in each particle are converted into distribution data in a characteristic parameter space. In the process, the distribution data provides two-dimension scattergram data F (X1, X2) in which data items X1 and X2 form coordinate axes respectively. Hemocytes are classified into granulocytes, lymphocytes, and monocytes on the basis of the two-dimension scattergram.
In the above particle analyzing apparatus, a distribution pattern on the scattergram allows classifying whether or not the sample is normal or abnormal. In addition, detailed investigation of the distribution pattern enables presuming the identity of disease. Thus, a case collection in which typical scattergrams in each disease are described is provided to users of the particle analyzing apparatus. Users compare scattergrams obtained with the particle analyzing apparatus with scattergrams described in the case collection, thereby finding similarities therebetween to use them as test data.
Such method involving much dependence on the subjective judgment of man, however, demands a considerable time in determining the identity of each disease. Besides, the result of judgment by this method is also ambiguous. Thus it is hard to say that the method is effective. Consequently there is need for an analyzing apparatus and a method therefor that facilitates a quantitative and simple analysis of the probability of each disease by representing in a value the degree of similarity between the scattergram obtained in the particle analyzing apparatus and the scattergram in the typical cases of disease.
On the other hand, the particle analyzing apparatus require a control for assuring that the apparatus themselves are operated in a favorable condition, or the quality control thereof. Conventionally, in the quality control, a parameter is determined that constitutes a goal in each measurement item in the apparatus. The accuracy control of the apparatus involves inspecting the fluctuation in the parameter. Any attempt of improving the precision in the quality control (a capacity of detecting that they are operated in a favorable condition), however, requires a larger number of parameters. Along with the multiplication of the number of dimensions from the two to three-dimensions in the distribution data obtained by the particle analyzing apparatus, the number of parameters to be controlled increases with the result that controlling such parameters demands more trouble and time.
Consequently, there is need for a particle analyzing apparatus that facilitates an accuracy control with more simple method and in shorter time.
In addition, when a particle analyzing apparatus is manufactured, it is necessary to evaluate distribution data obtained from the particle analyzer thus manufactured as to whether or not the data has reproducibility and stability (as to whether the same distribution data can be obtained when the same sample is analyzed many times). In other words, it is necessary to conduct a performance evaluation as to whether the particle analyzing apparatus can be shipped as a product. Conventionally the performance evaluation was conducted along with the quality control. Thus the evaluation required much trouble and time.
Consequently there is need for a particle analyzing apparatus that facilitates the performance evaluation with a simple method in a short time.
As an aside, Japanese laid-open patent No. HEI 3-131756 describes an automatic classifying device for blood cells for detecting and analyzing immature blood cells (abnormal blood cells) by using a hierarchic network through the input of form parameter, a concentration parameter, a color tone parameter and a texture parameter.